Rapid Determination of Cadmium: A Potentiometric Membrane Sensor based on Ninhydrin-Pyrogallol monoadduct as a New Ionophore

In this study, a cd2+ potentiometric ion selective membrane sensor was prepared based on the selective complexation between 4b,6,7,9b-tetrahydroxy-4bh-indeno[1,2-b]benzofuran-10(9bh)-one(ninhydrin-pyrogallol monoadduct) as ionophore and cd2+ ion. the electrode exhibits a nernstian response for cd2+ ion over a concentration range of 1.0×10-1 to 1.0×10-4 mol l-1 with a slope of 28 mv per decade. the limit of detection of the sensor is 7.0×10-5mol l-1. the sensor has a relatively fast response time (?5 s) and a useful working ph range of 3.0–7.0. interference of some cations was also evaluated. it was used as an indicator electrode in potentiometric titration of cd2+ with edta and in direct determination of cd2+ in water and wastewater samples. the results indicate that this electrode is sensitive for determination of cd2+